†Polycyathus Duncan 1876 (stony coral)
Anthozoa - Scleractinia - Caryophylliidae
Parent taxon: Caryophylliidae according to J. Stolarski 1991
Sister taxa: Antillocyathus, Aulocyathus, Axocyathus, Bourneotrochus, Caryophylliinae, Caryosmilia, Ceratotrochus, Ceriosmilia, Citharocyathus, Coelosmilia, Coenocyathus, Conotrochus, Crispatotrochus, Cyathoceras, Dasmosmilia, Deltocyathus, Desmophyllinae, Discoidocyathus, Eusmiliinae, Goniocorella, Helloceras, Heterocyathus, Kraterostrobilos, Lophelia, Odontocyathoides, Oxysmilia, Paracyathus, Parasmiliinae, Parasmilinae, Solenosmilia, Thecocyathinae, Turbinoliinae, Vaughanella, Vielicyathus
Subtaxa: none
Ecology: stationary low-level epifaunal microcarnivore